Drilling device



Oct. 13, 1953 J. M. PESTARINI DRILLING DEVICE Filed Oct. 6, 1949 Patented Oct. 13, 1953 UNITED STATES PATENT OFFICE DRILLING DEVICE Joseph Maximus Pestarini, Staten Island, N. Y.

Application October 6, 1949, Serial No. 119,974

10 Claims. 1

This invention relates to drilling machines. More particularly the invention concerns drilling devices used in mining, construction and related operations.

An object of this invention is to provide improved means for increasing the operative efliciency of a drilling device by imparting to the drill bit simultaneous rotating and percussing action. The percussing action is obtained, by repeated impacts on the drill bit.

Another object of the invention is to provide in combination with a drilling device, improved motor means, for operating the device, said means being adapted to stall without injury to the motor or its associated circuits, and further adapted to develop, while stalled, a relatively high torque; said motor means being adapted, further, to maintain a safe maximum speed.

A further object of this invention is to provide in combination with a drilling device an electric motor, supplied with a current, the intensity of which is kept below a predetermined limit irrespective of the rotational speed of the drill bit and electromagnetic means for percussing the drill bit while it rotates, said electromagnetic means being adapted to be supplied with a pulsating current.

The accompanying figure illustrates, schematically, an arrangement embodying the invention.

In the figure, I indicates the drilling device comprising a bit 2, a driving motor 3 for rotating the bit and transmitting its torque to said bit by means of a slidable mechanical coupling 4, mounted on the armature shaft thereof, which allows reciprocatory movement of the bit as it rotates. An electromagnet including winding 5, adapted to be energized intermittently and a movable armature 8 provides reciprocatory, percussive movement of the bit. Said movable armature 8 is adapted to engage a shoulder 32 I generator metadyne 9 shown in the figure as comprising an armature provided with four brushes per cycle. Two primary brushes a, c, are short circuited and two secondary brushes 1), d, are connected to the primary brushes a, c, of the motor metadyne 3. The metadyne 9 is also provided with a stator winding I I and a control rheostat 26 for controlling the output current that the generator 9 supplies through its secondary brushes b, d.

In the loop comprising the generator metadyne 9 and the motor metadyne 3, two other energy consumers 23, 24, such as motors or the like, may be inserted and supplied with energy by the metadyne 9 for operation independently of the motor metadyne 3.

The metadynes mentioned herein are rotating electric machines comprising an armature with a commutator and more than two brushes per cycle. The metadynes have been described in many United States patents, see for instance, Patents Nos. 2,055,240; 1,987,417; 2,038,380; 2,049,389; 2,079,465. A more complete description is given in Revue Generale de lElectricite, on March 8 and 15, August 16 and 23, November 22 and 29 and December 6, 1930, Paris.

A motor metadyne of the type referred to hereinabove is more fully described in the United States patent application, Serial No. 707,698, filed November 4, 1946. A generator metadyne of the type referred to hereinabove is more fully described in the British Patent No. 420,167.

Another generator metadyne I0 is shown supplying energy to the winding 5 of the electromagnet and is indicated as comprising two short circuited primary brushes a", c", and two secondary output brushes 1), d", per cycle. A stator winding I5 traversed by the output current, creates a flux opposing the armature flux created by said output current. Another stator winding I6 controls, by its ampere turns, the output current.

The generator metadynes 9 and ID are indicated as mounted on a common shaft which is driven by a prime mover not shown. On the same shaft is mounted a small auxiliary dynamo I I shunt excited through its field winding I1 and supplying direct current to an auxiliary circuit having conductors 30 and 3|.

A consumer 25, such as a motor or the like, may be inserted in the loop supplied with energy by the generator metadyne I0 for operation independently of the operation of drill I.

The generator 9 creates a practically constant current, the intensity of which is controlled by the ampere turns of the stator winding I4 which is energized by the constant voltage circuit through conductors 30, 3|. The rheostat 26 controls the current traversing winding I4.

The generator II! is adapted to create impulses of current at a low frequency. Said impulses are by the generator I0 is determined by the speed of rotation of the interruptor l3 which speedds controlled by a rheostat 20 inserted in the field winding circuit of the dynamo "iZIheintensit-y of the same pulsating current, .is,regulated by the rheostat I9 inserted in the circuit o'f'the Winding [6.

For each pulsation of the current traversing zthewinding of thegalectromagn et, ,the armature 284s perated {line shoulder 32, on ,thetbitis sub- ,iected t-to an impact while Isaid bit is also -rotated through coupling l.

it is important ,to ,note ;that the losses: due to V I claim:

1. A drilling device comprising a drill bit, means for rotating said bit including an electric motor, means for simultaneously percussing said tool including an electromagnet, coupling means between said rotating means and said bit permitting axial movement of said bit while said bit is rotating, dynamo electric means for supplying substantially constant electric current to said gelectric motor :at all gspeeds ofssaidL'mOtOr and =means-forsupplying a-pulsating current to said electromagnet.

' 2. A drilling device comprising a drill bit, means tfonrotating said bit including an electric motor the freguent interruption of the "current occur only .in ;the 551118 11, current. carrying circuit of .l the stator-winding LE-and :areozerot in the circuit comprisingt-thearmature of the generator metadyne In and the winding 5 of the electromagnet.

{Ifheconstant currentsupplied by thegenerator ':9 :to Liam-motor .6, traverses the armature of said.

jmotoryandthes-stator winding 5., creating thusa :starting torqueof ra predetermined Maine. The

,valueof said torguemn be regulated. by therheo- -stat,:-2-i connected in paralleliwith the-winding 1'7.

@Ihe :\vinding= 6 traversed Boy the {secondary cur- ,rent supplied by the {secondary ,brushes ,1), :d, of thermotonmetadyne 3,;creates;=a flux in theopposite direction an-d largerthan-the:fill fireat y ,the :secondary current -;of the -mo to r metadyne traversin its armature. The .rangeof motor :spcedds determined by ,means of rheostat 22. .flherefolze, with increasing ;speed, :,the .torgue di- ,min,ishes andgatia predeterminedspeedthetorque becomes zero. With-a substantially constant curof the metadyne type, means for simultaneously wpercussingssaid tool including an electromagnet, meansiorssupplying said motor metadyne with direct current comprising a metadyne generator, rmeainsifor supplying said electromagnet with a pulsating current, said'last mentioned means including ,a second metadyne genenator, said-"secand .metadyne generator being 5 provided ,with- ;a controlling stator 'l-winding traversed: bya pulsating current and means for modifyingtthe.- fre- .guency of said lastfmentionedrpulsatingscurrent. 3. :A:dri1ling device. comprisinga,drill bit;-.m flns for ifotating.-.sa,i bit includins-a-motor metadyne .said ,motor ,rnetadyne tbeing provided with ran armature, -:a pair of primary brushes "and a ;pair of secondary brushes pericycle and with -:-a plu- -rality of stator windings, emeans :for simultaneously percussingssaid abit including an electromagnet, means-for: sup lyingitheiprimatyrbrushes ofrsaid, motormetadyne with-iassubstantially,cen- =stant current, means for-supplyingisaidq electromagnet 'Wlth a pulsating current of a ;,predetermined frequency, .one of-said stator-windings having its magnetic axis .tsubstantially acoinicident with ,the axis, of {the flux -:createdrbywthenflurrent 4O traversing .the armature throu h -.its secondary -;thermeta dynes ,and-electromagnetyma-y be operated to provide rotary or impactgactionfor the'drill bit, independently of each other.

It is also understood that tools other than t ib ushes, :being traversed :by :said -.,oonstant ,current,anotheroftsaidrstator windin sabeingitrav- -:-ersed by said last mentioned-- trmature icurren rand {creating ea flux oppo ng and ;.;greater than fthe ,last ;mentionediarmature fluxaand, means ifcr ,controlling thecampere turns,createdxinzthe fir mentioned stator winding.

+1- ,aa rilling devic c mp isinga drillebitrme n for rotating said --bit including ,-electric gmotor, 'means :for, simultaneously;percussing1 sa-idgbittiineluding an electromagnet, means for {supplying saidelectromagnet with;a :r. u1 .ating current, said last mentioned means comprising :a generator imeta yn pr vid d wi h a centrol in stator -:winding, a pcircuit including said winding, :means f r peri d cally interru ting the current :in said circuit, andsmeans'l-for tallying :therate ofv interruption of the current ;in-sa-id:;circuit.

:5. =Atdrilling evi comprisin sardrillrbi tmeans for rotatin said -bit including an electric;motcr, means f'fQr simultaneously percussing said 1 bit including an electromagnet, means for suhplying said electromagnet .with, a pulsatingqcurrent,gsaid last mentioned means comprising a generator metadyne provided with -;an armature, output brushes and a -plurality of ;stator windings, zone of :said stator windings controlling :the -output current,'beingtraversedrby .azpulsating current of a predetermined ;frequency and a another oi said stator windingsrbeingmonnected inr-series-iwithzthe output brushes :of said :generzatonmetadyne .and creating a-;fl ux opposing the armature :flux due .to the currenttraversingithe armature :t-hrough said-outputbrushes. I

45. A ,dri1 ins d vic omprisin .a :drill 21311 means for rotating said bit comprising a motor metadyne, said motor metadyne including an armature, a pair of primary brushes and a pair of secondary brushes per cycle, and a plurality of stator windings, means for supplying the primary brushes of said motor metadyne with a substantially constant current, one of said stator windings having its magnetic axis substantially coincident with the axis of the flux created by the current traversing the armature through the secondary brushes being traversed by said constant current, another of said stator windings being traversed by said last mentioned armature current and creating a flux opposing and greater than the last mentioned armature flux, and means for controlling the ampere turns created in the first mentioned stator winding.

7. A drilling device comprising a drill bit, means for imparting a percussive and reciprocatory action to said drill bit comprising an electromagnet, means for supplying a pulsating current to said magnet comprising a generator metadyne, said metadyne including a stator winding for controlling the output current thereof, means for supplying said stator winding with a pulsating current and means for modifying the frequency of said last mentioned pulsating current.

8. A drilling device comprising a drill bit, means for rotating said bit including an electric motor, said motor including a field winding creating ampere turns decreasing with an increase in the speed thereof, means for percussing said bit including an electromagnet, means for supplying said motor with a substantially constant current at speeds ranging from zero to maximum, means for supplying said electromagnet with a pulsating current of predetermined frequency.

9. In combination, a tool and means for imparting combined rotary and impacting movement to said tool comprising electromagnetic means, rotary electrical means for supplying current to said electromagnetic means, said rotary electrical means comprising a control winding, a source of direct current, interruptor means in circuit with said source of current and said control winding for pulsating the current traversing said control winding whereby to affect the output current of said rotary electrical means supplied to said electromagnetic means and to provide impulse operation thereof, electric motor means, means for coupling said motor to said tool, rotary electrical means for supplying said motor with current, said last mentioned rotary electrical means including a control winding in circuit with said source of current for controlling the current output of said last mentioned rotary electrical means.

10. Means for rotating a tool comprising in combination, means for supplying substantially constant current, a motor adapted to be operatively connected to said tool, said motor comprising an armature including a pair of primary brushes and a pair of secondary brushes displaced therefrom, a stator winding in circuit with said secondary brushes, a second stator winding in circuit with said current supply means and said primary brushes, said motor being adapted to operate under stalling conditions without injury thereto.

JOSEPH MAXIMUS PESTARINI.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,892,517 Pennington Dec. 27, 1932 1,987,417 Pestarini Jan. 8, 1935 2,020,945 Hild Nov. 12, 1935 2,038,380 Pestarini Apr. 21, 1936 2,049,389 Pestarini July 28, 1936 2,051,249 Edwards Aug. 18, 1936 2,055,240 Pestarini Sept. 22, 1936 2,079,465 Pestarini May 4, 1937 2,091,680 Greenlee Aug. 31, 1937 FOREIGN PATENTS Number Country Date 420,167 Great Britain Nov. 27, 1934 OTHER REFERENCES Revue Generale de lElectricite, 1930 (March 8, March 15, August 16, August 23, November 22, November 29, December 6), Paris. 

